New phosphorus reduction targets take pressure off Ontario agriculture

by BETTER FARMING STAFF

Canada’s Lake Erie phosphorus reduction targets are a lot smaller than those earmarked for the lake’s south side, a new binational agreement indicates.

In February, Canada and the United States agreed to slash annual phosphorus loading into the troubled lake by 40 per cent of 2008 levels.

In recent years toxic algae blooms have threatened water quality and compromised some drinking water systems. The blooms are linked to increasing amounts of nutrients, including dissolved phosphorus, leaching into the lake, and agriculture has been identified as a potential culprit.

Establishing targets by February was a condition of the Great Lakes Water Quality Agreement both countries signed in 2012, says Sandra George, nutrient issues coordinator for Environment and Climate Change Canada.

The two countries must come up with a plan of action to implement the reduction by February 2018, George adds during a Thursday telephone interview.

The binational reduction target agreement is different from a collaborative agreement signed in June by Ontario’s premier as well as Michigan and Ohio governors to reduce phosphorus inputs by 40 per cent compared to 2008 levels, she says. The June 2015 agreement “only dealt with one particular piece of the whole pie” and only covers the western basin, the lake’s shallowest area, which is at greatest risk.

In contrast, the targets identified in February cover the lake’s western and central basin as well as some tributaries, she says.

The June and February agreement targets are consistent with each other, she says.

The June agreement lists 2025 as the goal to achieve total reduction targets, notes Bianca Jamieson, Ontario Ministry of Agriculture, Food and Rural Affairs spokesperson, in an email on Friday. An aspirational interim goal is achieving a 20 per cent reduction in loading by 2020.

According to Binational.net, an information website maintained by Environment and Climate Change Canada and the U.S. Environmental Protection Agency, the two countries aim to reduce the lake’s annual phosphorus load to 6,000 tonnes or 3,528 tonnes less than what the loading was in 2008. (Loading is the mass of phosphorus entering the lake).

The website also identifies the watersheds to be addressed: the Thames River and Leamington tributaries in Canada and, in the United States, the Maumee, Portage, Sandusky and Huron Rivers, River Raisin, and Toussaint Creek. A 40 per cent reduction in phosphorus loading is the target for the watersheds, the website says.

Most of the onus will be on the United States, whose overall target is reducing 3,316 tonnes; Canada’s is 212 tonnes.

The phosphorus load in Lake Erie fluctuated significantly in the 10-year period from 2004 to 2014. A 2014 Lake Erie Ecosystem Priority report from the International Joint Commission indicates loadings peaked in 2007 at 12,000 tonnes and in 2011, phosphorus entering Lake Erie from external sources was more than 8,500 tonnes. (The commission advises the two national governments about issues in shared waters).

George credits the two countries’ vastly different targets to differences in watershed area — there are twice as many watersheds in the United States contributing to the lake’s problem areas compared to Canada — and the amount of phosphorus each country generates. The United States also “loads more per sector per hectare as well,” she says. The distribution of their sources is also different.

“So all of those things come into play.”

Ferreting out where the most phosphorus loading is coming from is the federal environment department’s current task. Once the hot spots are identified, work will begin to identify source specifics and how much each might be contributing to the issue.

Using the Thames River as an example, “it could be predominantly point source, if we were looking around London — and I’m just using these as examples; because as I said we’re working on this right now; it could be a real 50/50 point source mix,” George says. (A point source is an identifiable source of pollution, such as a sewage plant or a drain outlet. An example of a non-point source is runoff from an eroded field.)
 
It’s too early to blame specific agriculture sources north of the border. Phosphorus related to manure applications, for example, “is only relevant in certain areas. We’re not seeing livestock everywhere. Whether that’s a primary contributor or not, we don’t know yet,” she says.

George says they are trying to be very careful about how they approach the source analysis and “make sure we thoroughly understand the sources and the relative contributions of sources and have a good justification for it.”

The problem is complicated and so too will be the solution, she says.

Sectors will be engaged “all the way through” the development of the plan of action, she says, noting that the federal government will begin to seek input as soon as some of its analysis “starts to come to fruition.”

The effort is being undertaken in consultation with agricultural agencies at both the provincial and federal level as well as with the Ontario Ministry of the Environment and Climate Change. “We’re hopeful that we can bring municipal jurisdictions and the agricultural sector into it as well so we have a consensus by the time we get to February 2018,” she says.

For the past five years, Environment and Climate Change Canada has stepped up monitoring rivers that might be contributing to the problem but George says the program is temporarily suspended while the ministry waits for funding decisions from the next federal budget.

Certain rivers have been, and continue to be monitored by the province and other agencies, she says. BF